Laser-transparent pbt with organic additives

ABSTRACT

Use of thermoplastic molding compositions comprising, as essential components,
     A) a polyester,   B) from 20 to 200 mmol/kg of polyester A) of at least one compound of the general formula (I)   

     
       
         
         
             
             
         
       
     
     where
 
respectively independently at any position
     -A 1 - is —NR—, —O—, —S—, —CH=A 4 - where R is H or C 1-6 -alkyl, A 4  is N or CH   A 2  is COOX or OX, where X is Li, Na, K, Rb, Cs, Mg/2, Ca/2, Sr/2, Ba/2, Al/3   A 3  is C 1-6 -alkyl, C 6-12 -aryl, O 7-13 -alkaryl, C 7-13 -aralkyl, O—C 1-6 -alkyl, O—C 6-12 -aryl, O—C 7-13 -alkaryl, O—C 7-13 -aralkyl, COOX′, OX′, SX′, SO 3 X′, where X′ is H or X, S—C 1-6 -alkyl, S—C 6-12 -aryl, NR 2 , halogen, NO 2 ,   n is an integer from 1 to 4, and   m is an integer from 0 to 4−n, where m=1, if A 3 =NO 2 ,
 
with the proviso that the number of mmol is based on the group(s) COOX and OX and SX′ where X′═X, to the extent that these are present in the compound of the general formula (I), and also moreover
   C) from 0 to 230% by weight of further added substances, based on the weight of component A),
 
for producing laser-transparent moldings of any type.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application61/353,674 filed on Jun. 11, 2010, which is incorporated by reference.

BACKGROUND OF THE INVENTION

The invention relates to the use of thermoplastic molding compositionscomprising

A) a polyester,B) from 20 to 200 mmol/kg of polyester A) of at least one compound ofthe general formula (I)

whererespectively independently at any position

-   -A¹- is —NR—, —O—, —S—, —CH=A⁴- where R is H or C₁₋₆-alkyl, A⁴ is N    or CH-   A² is COOX or OX, where X is Li, Na, K, Rb, Cs, Mg/2, Ca/2, Sr/2,    Ba/2, Al/3-   A³ is C₁₋₆-alkyl, C₆₋₁₂-aryl, C₇₋₁₃-alkaryl, C₇₋₁₃-aralkyl,    O—C₁₋₆-alkyl, O—C₆₋₁₂-aryl, O—C₇₋₁₃-alkaryl, O—C₇₋₁₃-aralkyl, COOX′,    OX′, SX′, SO₃X′, where X′ is H or X, S—C₁₋₆-alkyl, S—C₆₋₁₂-aryl,    NR₂, halogen, NO₂,-   n is an integer from 1 to 4, and-   m is an integer from 0 to 4−n, where m=1, if A³=NO₂,    -   with the proviso that the number of mmol is based on the        group(s) COOX and OX and SX′ where X′═X, to the extent that        these are present in the compound of the general formula (I),        and also moreover-   C) from 0 to 230% by weight of further added substances, based on    the weight of component A), for producing laser-transparent moldings    of any type.

The invention further relates to the use of the laser-transparentmoldings for producing moldings by means of laser transmission weldingprocesses, to processes for producing moldings of this type, and also tothe use of these in various application sectors.

Components B) of this type have been described by way of example inPolymer Engineering and Science 1990, BO (5), pp. 270 ff, and 1995, 35(17), pp. 1407 ff, Journal of Appl. Pol. Sci. 2004, 93, pp. 590 ff, andalso U.S. Pat. No. 4,393,178, and EP-A-0 251 732, as nucleators forcompounded PET materials. The optical properties of the compoundedmaterials were not studied.

There are various existing processes for the welding of plasticsmoldings (Kunststoffe 87, (1997), 11, 1632-1640). Precondition for astable weld in the widely used heated-tool welding process and vibrationwelding process (e.g. for motor-vehicle intake manifolds) is adequatesoftening of the adherends in the contact zone prior to the actualconnection step.

Laser transmission welding, in particular using diode lasers, has beenincreasingly widely used recently as a method providing an alternativeto vibration welding and heated-tool welding.

The technical literature describes fundamental principles of lasertransmission welding (Kunststoffe 87, (1997) 3, 348-350; Kunststoffe 88,(1998), 2, 210-212; Kunststoffe 87 (1997) 11, 1632-1640;Plastverarbeiter 50 (1999) 4, 18-19; Plastverarbeiter 46 (1995) 9,42-46).

Precondition for the use of laser transmission welding is that theradiation emitted by the laser first penetrates a molding which hasadequate transparency for laser light of the wavelength used and whichin this application is hereinafter termed laser-transparent molding, andthen is absorbed in a thin layer by a second molding which is in contactwith the laser-transparent molding and hereinafter is calledlaser-absorbent molding. Within the thin layer which absorbs the laserlight, the laser energy is converted into heat, and this leads tomelting within the contact zone and finally to a weld which bonds thelaser-transparent molding to the laser-absorbent molding.

Laser transmission welding usually uses lasers in the wavelength rangefrom 600 to 1200 nm. Within the wavelength range of the lasers used forthe thermoplastics welding, the usual lasers are Nd:YAG lasers (1064 nm)or high-power diode lasers (from 800 to 1000 nm). When the termslaser-transparent and laser-absorbent are used hereinafter, they alwaysrelate to the abovementioned wavelength range.

The laser-transparent molding, unlike the laser-absorbent molding,requires high laser transparency within the preferred wavelength range,so that the laser beam can penetrate as far as the area of the weld,with the energy level required. An example of a method used to measurecapability to transmit IR laser light uses a spectrophotometer and anintegrating photometer sphere. This measurement arrangement also detectsthe diffuse fraction of the transmitted radiation. The measurement ismade not only at a single wavelength but within a spectral range whichcomprises all of the laser wavelengths currently used for the weldingprocedure.

Users presently have access to a number of laser-welding-processvariants based on the transmission principle. By way of example, contourwelding is a sequential welding process in which either the laser beamis conducted along a freely programmable weld contour or the componentis moved relatively to the immovable laser. In the simultaneous weldingprocess, the linear radiation emitted from individual high-power diodesis arranged along the contour of the weld. The melting and welding ofthe entire contour therefore take place simultaneously. Thequasi-simultaneous welding process is a combination of contour weldingand simultaneous welding. Galvanometric mirrors (scanners) are used toconduct the laser beam at very high velocity at 10 m/s or more along thecontour of the weld. The high traverse rate provides progressive heatingand melting of the region of the joint. In comparison with thesimultaneous welding process, there is high flexibility for alterationsin the contour of the weld. Mask welding is a process in which a linearlaser beam is moved transversely across the adherends. A mask is usedfor controlled screening of the radiation, and this impacts the area tobe joined only where welding is intended. The process can produce veryprecisely positioned welds. These processes are known to the personskilled in the art and are described by way of example in “HandbuchKunststoff-Verbindungstechnik” [Handbook of plastics bonding technology](G. W. Ehrenstein, Hanser, ISBN 3-446-22668-0) and/or DVS-Richtlinie2243 “Laserstrahlschweiβen thermoplastischer Kunststoffe” [GermanWelding Society Guideline 2243 “Laser welding of thermoplastics”].

Irrespective of the process variant used, the laser welding process ishighly dependent on the properties of the materials of the twoadherends. The degree of laser transparency (LT) of the transparentcomponent has a direct effect on the speed of the process, through theamount of energy that can be introduced per unit of time. The inherentmicrostructure, mostly in the form of spherulites, of semicrystallinethermoplastics generally gives them relatively low laser transparency.These spherulites scatter the incident laser light to a greater extentthan the internal structure of a purely amorphous thermoplastic:back-scattering leads to reduced total amount of transmitted energy, anddiffuse (lateral) scattering often leads to broadening of the laser beamand therefore to impaired weld precision. These phenomena areparticularly evident in polybutylene terephthalate (PBT), which incomparison with other thermoplastics that crystallize well, such as PA,exhibits particularly low laser transparency and a high level of beamexpansion. PBT therefore continues to be comparatively little used asmaterial for laser-welded components, although other aspects of itsproperty profile (e.g. good dimensional stability and low waterabsorption) make it very attractive for applications of this type.Although semicrystalline morphology is generally unhelpful for highlaser transparency, it provides advantages in terms of other properties.By way of example, semicrystalline materials continue to have mechanicalstrength above the glass transition point and generally have betterchemicals resistance than amorphous materials. Materials thatcrystallize rapidly also provide processing advantages, in particularquick demoldability and therefore short cycle times. It is thereforedesirable to combine semicrystallinity with rapid crystallization andhigh laser transparency.

There are various known approaches to laser-transparency increase inpolyesters, in particular PBT. In principle, these can be divided intoblends/mixtures and refractive-index matching.

The approach using blends/mixtures is based on “dilution” of thelow-laser-transparency PBT by using a high-laser-transparency partner inthe blend/mixture. Examples of this are found in the followingspecifications: JP2004/315805A1 (PBT+PC/PET/SA+filler+elastomer),DE-A1-10330722 (generalized blend of a semicrystalline thermoplasticwith an amorphous thermoplastic in order to increase LT; spec.PBT+PET/PC+glass fiber), JP2008/106217A (PBT+copolymer with1,4-cyclohexanedimethanol; LT of 16% increased to 28%). A disadvantagehere is that the resultant polymer blends inevitably have propertiesmarkedly different from those of products based predominantly on PBT asmatrix.

The refractive-index-matching approach is based on the differentrefractive indices of amorphous and crystalline PBT, and also of thefillers. By way of example, comonomers have been used here:JP2008/163167 (copolymer of PBT and siloxane), JP2007/186584(PBT+bisphenol A diglycidyl ether) and JP2005/133087(PBT+PC+elastomer+high-refractive-index silicone oil) may be mentionedas examples. Although this leads to an increase in laser transparency,this is achieved with loss of mechanical properties. Therefractive-index difference between filler and matrix can also bereduced, see JP2009/019134 (epoxy resin coated onto glass fibers inorder to provide matching at the optical interface between fiber andmatrix), or JP2007/169358 (PBT with high-refractive-index glass fiber).Starting materials of this type are, however, disadvantageous because oftheir high costs and/or the additional stages that they require withinthe production process.

The effects achieved in relation to laser-transparency increase are alsooverall relatively minor and therefore not entirely satisfactory.

BRIEF SUMMARY OF THE INVENTION

A laser-transparent molding of any type, comprising a thermoplasticmolding compositions comprising,

-   A) a polyester,-   B) from 20 to 200 mmol/kg of polyester A) of at least one compound    of the general formula (I)

whererespectively independently at any position-A¹- is —NR—, —O—, —S—, —CH=A⁴- where R is H or C₁₋₆-alkyl, A⁴ is N orCHA² is COOX or OX, where X is Li, Na, K, Rb, Cs, Mg/2, Ca/2, Sr/2, Ba/2,Al/3A³ is C₁₋₆-alkyl, C₆₋₁₂-aryl, C₇₋₁₃-alkaryl, C₇₋₁₃-aralkyl,O—C₁₋₆-alkyl, O—C₆₋₁₂-aryl, O—C₇₋₁₃-alkaryl, O—C₇₋₁₃-aralkyl, COOX′,OX′, SX′, SO₃X′, where X′ is H or X, S—C₁₋₆-alkyl, S—C₆₋₁₂-aryl, NR₂,halogen, NO₂,n is an integer from 1 to 4, andm is an integer from 0 to 4−n, where m=1, if A³=NO₂,with the proviso that the number of mmol is based on the group(s) COOXand OX and SX′ where X′═X, to the extent that these are present in thecompound of the general formula (I); and also moreoverC) from 0 to 230% by weight of further added substances, based on theweight of component A).

The object of the present invention was therefore to improve the lasertransparency of polyesters, and to provide polyesters suitable for lasertransmission welding. Accordingly, the molding compositions defined inthe introduction, and the use of these, were discovered. The dependentclaims give preferred embodiments.

The molding compositions of the invention comprise, as component A), atleast one thermoplastic polyester.

DETAILED DESCRIPTION OF THE INVENTION

At least one of the polyesters in component A) is preferably asemicrystalline polyester. Preference is given to components A) whichcomprise at least 50% by weight of semicrystalline polyesters. Thisproportion is particularly preferably at least 70% by weight (based ineach case on 100% by weight of A)).

Based on 100% of the molding compositions made of A) to C) (i.e.inclusive of C)), these comprise

-   -   from 30 to 100% by weight of A)+B), preferably from 50 to 100%        by weight;    -   from 0 to 70% by weight of C), preferably from 0 to 50% by        weight.

An essential factor within the above relative magnitudes is that theproportion of component B) is always based on the polyester, since thisratio is intended to lie within the above-mentioned boundaries. Theadded substances C) can have an effect on laser transparency. Thiseffect depends in essence on the scattering and absorption properties ofthe added substances. The optical properties of the compounded materialare in essence a summation of the optical properties of the matrix ofthe invention (components A+B) and of those of the additives (componentsC).

The polyesters A) generally used are based on aromatic dicarboxylicacids and on an aliphatic or aromatic dihydroxy compound.

A first group of preferred polyesters is that of polyalkyleneterephthalates having in particular from 2 to 10 carbon atoms in thealcohol moiety.

Polyalkylene terephthalates of this type are known per se and aredescribed in the literature. Their main chain comprises an aromatic ringwhich derives from the aromatic dicarboxylic acid.

There may also be substitution in the aromatic ring, e.g. by halogen,such as chlorine or bromine, or by C₁-C₄-alkyl groups, such as methyl,ethyl, iso- or n-propyl, or n-, iso- or tert-butyl groups.

These polyalkylene terephthalates may be produced by reacting aromaticdicarboxylic acids, or their esters or other ester-forming derivatives,with aliphatic dihydroxy compounds in a manner known per se.

Preferred dicarboxylic acids are 2,6-naphthalenedicarboxylic acid,terephthalic acid and isophthalic acid or mixtures of these. Up to 30mol %, preferably not more than 10 mol %, of the aromatic dicarboxylicacids may be replaced by aliphatic or cycloaliphatic dicarboxylic acids,such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acids andcyclohexanedicarboxylic acids.

Preferred aliphatic dihydroxy compounds are diols having from 2 to 6carbon atoms, in particular 1,2-ethanediol, 1,3-propanediol,1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol,1,4-cyclohexanedimethanol and neopentyl glycol, and mixtures of these.

Particularly preferred polyesters (A) are polyalkylene terephthalatesderived from alkanediols having from 2 to 6 carbon atoms. Among these,particular preference is given to polyethylene terephthalate,polypropylene terephthalate and polybutylene terephthalate, and mixturesof these. Preference is also given to PET and/or PBT which comprise, asother monomer units, up to 1% by weight, preferably up to 0.75% byweight, of 1,6-hexanediol and/or 2-methyl-1,5-pentanediol.

The intrinsic viscosity of the polyesters (A) is generally in the rangefrom 50 to 220, preferably from 80 to 160 (measured in 0.5% strength byweight solution in a phenol/o-dichlorobenzene mixture in a ratio byweight of 1:1 at 25° C.) to ISO 1628.

Particular preference is given to polyesters whose carboxy end groupcontent is from 0 to 100 meq/kg of polyester, preferably from 10 to 50meq/kg of polyester and in particular from 15 to 40 meq/kg of polyester.Polyesters of this type may be produced, for example, by the process ofDE-A 44 01 055. The carboxy end group content is usually determined bytitration methods (e.g. potentiometry).

Particularly preferred molding compositions comprise, as component A), amixture of polyesters, at least one being PBT. An example of theproportion of the polyethylene terephthalate in the mixture ispreferably up to 50% by weight, in particular from 10 to 35% by weight,based on 100% by weight of A).

It is also advantageous, if appropriate, to use PET recyclates (alsotermed scrap PET) in a mixture with polyalkylene terephthalates, such asPBT.

Recyclates are Generally:

1) those known as post-industrial recyclates: these are productionwastes during polycondensation or during processing, e.g. sprues frominjection molding, start-up material from injection molding orextrusion, or edge trims from extruded sheets or films.2) post-consumer recyclates: these are plastics items which arecollected and treated after utilization by the end consumer. Blow-moldedPET bottles for mineral water, soft drinks and juices are easily thepredominant items in terms of quantity.

Both types of recyclate may be used either as regrind or in the form ofpellets. In the latter case, the crude recycled materials are isolatedand purified and then melted and pelletized using an extruder. Thisusually facilitates handling and free-flowing properties, and meteringfor further steps in processing.

The recycled materials used may either be pelletized or in the form ofregrind. The edge length should not be more than 10 mm and shouldpreferably be less than 8 mm.

Because polyesters undergo hydrolytic cleavage during processing (due totraces of moisture) it is advisable to predry the recycled material.Residual moisture content after drying is preferably <0.2%, inparticular <0.05%.

Another group to be mentioned is that of fully aromatic polyestersderiving from aromatic dicarboxylic acids and aromatic dihydroxycompounds.

Suitable aromatic dicarboxylic acids are the compounds previouslydescribed for the polyalkylene terephthalates. The mixtures preferablyused are made from 5 to 100 mol % of isophthalic acid and from 0 to 95mol % of terephthalic acid, more particularly mixtures of about 80% ofterephthalic acid with 20% of isophthalic acid to approximatelyequivalent mixtures of these two acids.

The aromatic dihydroxy compounds preferably have the general formula

in which Z is an alkylene or cycloalkylene group having up to 8 carbonatoms, an arylene group having up to 12 carbon atoms, a carbonyl group,a sulfonyl group, an oxygen atom or sulfur atom, or a chemical bond, andin which m has the value from 0 to 2. The phenylene groups in thecompounds may also have substitution by C₁-C₆-alkyl groups or alkoxygroups, and fluorine, chlorine, or bromine.

Examples of parent compounds for these compounds are dihydroxybiphenyl,

di(hydroxyphenyl)alkane,di(hydroxyphenyl)cycloalkane,di(hydroxyphenyl)sulfide,di(hydroxyphenyl)ether,di(hydroxyphenyl)ketone,di(hydroxyphenyl)sulfoxide,α,α′-di(hydroxyphenyl)dialkylbenzene,di(hydroxyphenyl)sulfone, di(hydroxybenzoyl)benzene,resorcinol, andhydroquinone, and also the ring-alkylated and ring-halogenatedderivatives of these.

Among these, preference is given to

4,4′-dihydroxybiphenyl,2,4-di(4′-hydroxyphenyl)-2-methylbutane,α,α′-di(4-hydroxyphenyl)-p-diisopropylbenzene,2,2-di(3′-methyl-4′-hydroxyphenyl)propane, and2,2-di(3′-chloro-4′-hydroxyphenyl)propane,and in particular to2,2-di(4′-hydroxyphenyl)propane,2,2-di(3′,5-dichlorodihydroxyphenyl)propane,1,1-di(4′-hydroxyphenyl)cyclohexane,3,4′-dihydroxybenzophenone,4,4′-dihydroxydiphenyl sulfone and2,2-di(3′,5′-dimethyl-4′-hydroxyphenyl)propaneor a mixture of these.

It is, of course, also possible to use mixtures of polyalkyleneterephthalates and fully aromatic polyesters. These generally comprisefrom 20 to 98% by weight of the polyalkylene terephthalate and from 2 to80% by weight of the fully aromatic polyester.

It is, of course, also possible to use polyester block copolymers, suchas copolyetheresters. Products of this type are known per se and aredescribed in the literature, e.g. in U.S. Pat. No. 3,651,014.Corresponding products are also available commercially, e.g. Hytrel®(DuPont).

In the invention, the term polyester includes halogen-freepolycarbonates. Examples of suitable halogen-free polycarbonates arethose based on biphenols of the general formula

in which Q is a single bond, a C₁-C₈-alkylene group, a C₂-C₃-alkylidenegroup, a C₃-C₆-cycloalkylidene group, a C₆-C₁₂-arylene group, or else—O—, —S— or —SO₂—, and m is a whole number from 0 to 2.

The phenylene radicals of the biphenols may also have substituents, suchas C₁-C₆-alkyl or C₁-C₆-alkoxy.

Examples of preferred biphenols of the formula are hydroquinone,resorcinol, 4,4′-dihydroxydiphenyl, 2,2-bis(4-hydroxyphenyl)propane,2,4-bis(4-hydroxyphenyl)-2-methylbutane and1,1-bis(4-hydroxyphenyl)cyclohexane. Particular preference is given to2,2-bis(4-hydroxyphenyl)propane and 1,1-bis(4-hydroxyphenyl)cyclohexane,and also to 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.

Either homopolycarbonates or copolycarbonates are suitable as componentA, and preference is given to the copolycarbonates of bisphenol A, aswell as to bisphenol A homopolymer.

Suitable polycarbonates may be branched in a known manner, specificallyand preferably by incorporating from 0.05 to 2.0 mol %, based on thetotal of the biphenols used, of at least trifunctional compounds, forexample those having three or more phenolic OH groups.

Polycarbonates which have proven particularly suitable have relativeviscosities η_(rel) of from 1.10 to 1.50, in particular from 1.25 to1.40. This corresponds to an average molar mass M_(W) (weight average)of from 10 000 to 200 000 g/mol, preferably from 20 000 to 80 000 g/mol.

The biphenols of the general formula are known per se or can be producedby known processes.

The polycarbonates may, for example, be produced by reacting thebiphenols with phosgene in the interfacial process, or with phosgene inthe homogeneous-phase process (known as the pyridine process), and ineach case the desired molecular weight is achieved in a known manner byusing an appropriate amount of known chain terminators. (In relation topolydiorganosiloxane-containing polycarbonates see, for example, DE-A 3334 782.)

Examples of suitable chain terminators are phenol, p-tert-butylphenol,or else long-chain alkylphenols, such as 4-(1,3-tetramethylbutyl)phenol,as in DE-A 28 42 005, or monoalkylphenols, or dialkylphenols with atotal of from 8 to 20 carbon atoms in the alkyl substituents, as in DE-A35 06 472, such as p-nonylphenyl, 3,5-di-tert-butylphenol,p-tert-octylphenol, p-dodecylphenol, 2-(3,5-dimethylheptyl)phenol and4-(3,5-dimethylheptyl)phenol.

For the purposes of the present invention, halogen-free polycarbonatesare polycarbonates made from halogen-free biphenols, from halogen-freechain terminators and, if appropriate, from halogen-free branchingagents, where the content of subordinate amounts at the ppm level ofhydrolyzable chlorine, resulting, for example, from the production ofthe polycarbonates with phosgene in the interfacial process, is notregarded as meriting the term halogen-containing for the purposes of theinvention. Polycarbonates of this type with contents of hydrolyzablechlorine at the ppm level are halogen-free polycarbonates for thepurposes of the present invention.

Other suitable components A) which may be mentioned are amorphouspolyester carbonates, where phosgene has been replaced, during thepreparation, by aromatic dicarboxylic acid units, such as isophthalicacid and/or terephthalic acid units. For further details reference maybe made at this point to EP-A 711 810.

Other suitable copolycarbonates with cycloalkyl radicals as monomerunits have been described in EP-A 365 916.

It is also possible to replace bisphenol A with bisphenol TMC.Polycarbonates of this type are commercially available from Bayer withthe trademark APEC HT®.

The molding compositions of the invention comprise, as component B),from 20 to 200 mmol/kg of polyester A), preferably from 25 to 140mmol/kg of polyester A), in particular from 30 to 110 mmol/kg ofpolyester A), of at least one compound of the general formula (I).

The number of mmol of component B) here is based on the group(s) COOXand OX and SX′, where X′═X in the radicals A² and optionally A³ of thecompounds of the general formula (I). One group COOX or, respectively,OX or, respectively, SX′, where X′═X corresponds to one equivalent ormole. The data in mmol therefore gives the molar amount of groups COOXand OX and SX′, where X′═X in total (i.e. the sum thereof). The numberof nucleators is important for the laser transparency of the polyester.This is why the amount of the nucleator B) to be used is stated in aform based on the molar concentration salt groups, rather than in % byweight. The amounts of nucleator or nucleating agent are stated in theexamples both in % by weight and in mmol/kg of polyester.

Reference can be made to DIN 32 625 of December 1998 for thedetermination of molar amounts using equivalents.

Reference can also be made to J. S. Fritz, G. H. Schenk, QuantitativeAnalytische Chemie [Quantitative Analytical Chemistry], Viehweg, 1989,pp. 8 to 9.

It is also possible that free carboxy groups (COOH) or hydroxy groups(OH), or corresponding sulfur systems, are present as radicals A³ in thecompounds of the general formula (I). These appear to contribute little,or nothing, to the nucleating effect, and this amount is therefore notincluded in the calculation for determining the mmol/kg of polyester A).In the case of partially neutralized carboxy groups or hydroxy groups,it is only the neutralized portion that is included in the calculation.

The polyesters A) generally react with the salt compounds B), whereuponthe metal cation of the compounds B) is transferred to terminal carboxygroups of the polyesters. The nucleating effect of component B) isdetectable even with very small concentrations. Surprisingly, lasertransparency falls at very small concentrations of component B), and itis only at higher concentrations that a rise in laser transparency isachieved.

Component B) is a component selected from one or more compounds of thegeneral formula I)

whererespectively independently at any position

-   -A¹- is —NR—, —S—, —CH=A⁴- where R is H or C₁₋₆-alkyl, A⁴ is N or CH-   A² is COOX or OX, where X is Li, Na, K, Rb, Cs, Mg/2, Ca/2, Sr/2,    Ba/2, Al/3-   A³ is C₁₋₆-alkyl, C₆₋₁₂-aryl, C₇₋₁₃-alkaryl, C₇₋₁₃-aralkyl,    O—C₁₋₆-alkyl, O—C₆₋₁₂-aryl, O—C₇₋₁₃-alkaryl, O—C₇₋₁₃-aralkyl, COOX′,    OX′, SX′, SO₃X′, where X′ is H or X, S—C₁₋₆-alkyl, S—C₆₋₁₂-aryl,    NR₂, halogen, NO₂,-   n is an integer from 1 to 4, and-   m is an integer from 0 to 4−n, where m=1, if A³=NO₂,    with the proviso that the number of mmol is based on the group(s)    COOX and OX and SX′ where X′═X, to the extent that these groups are    present in the compound of the general formula (I).

The compounds can therefore be five-membered or six-membered aromaticring systems. The five-membered ring systems are heterocycles, but thesix-membered rings can be nitrogen heterocycles or aromatic cycliccompounds comprising only carbon and therefore formally derived frombenzene.

It is preferable that n in the compounds of the general formula (I) hasthe value 1 or 2.

It is preferable that m in the compounds of the general formula (I) hasthe value 0 or 1 or 2.

It is particularly preferable here that n has the value 1. It isparticularly preferable that m has the value 0 or 1.

Particular preference is therefore given to combinations of n=1 withm=0, and n=1 with m=1.

X is preferably Li, Na, K, Rb, or Cs particularly Li, Na, or K,specifically Na. It is also possible that mixtures of two or more ofthese counterions are present.

A³ is particularly preferably C₁₋₆-alkyl-, OX, SO₃X, halogen, or NO₂.

R in the compounds of the general formula (I) is preferably H.

The expression Mg/2, Ca/2, Sr/2, Ba/2, Al/3 means an equivalent amountof the metal or metal ion required to neutralize a COOH or OH or SH orSO₃H group. Since magnesium, calcium, strontium and barium are divalent,one corresponding ion is sufficient to neutralize two carboxy or hydroxygroups, or SH or SO₃H. One aluminum ion is sufficient to neutralizethree carboxy or hydroxy groups. When said counterions are present, theamounts of the cyclic organic compounds therefore have to be doubled ortripled in order to obtain a number of metal atoms or ions that is aninteger.

Preferred compounds of the general formula (I) are listed below and inthe examples.

The sodium salts are preferred. The compound of the general formula (I)preferably derives from salicylic acid, benzoic acid, or phenol, wherethe aromatic ring can bear further substituents, but no further hydroxyor carboxy groups are present.

Examples are sodium benzoate, sodium 4-tert-butylbenzoate, disodiumsalicylate, sodium isonicotinate, sodium 2-thiophenecarboxylic acid,sodium pyrrole-2-carboxylate, sodium phenolate, disodium4-hydroxybenzenesulfonate, lithium 5-sulfoisophthalate, sodium2-nitrobenzoate, sodium 2-chlorobenzoate, sodium 2,4-dichlorobenzoate,and sodium phenylacetate.

It is preferable that all of the carboxy groups and hydroxy groups inthe compounds of the general formula (I) have been neutralized.

The proportion by weight of component B) can be defined approximately aspreferably from 0.3 to 2.0% by weight, particularly preferably from 0.4to 1.5% by weight, with particular preference from 0.5 to 1% by weight,based on component A). However, the above data in mmol/kg of polyesterA) is more reliable, because of the different molecular weights andequivalent weights of nucleating salt groups COOX, OX, SX′, where X′═X.

The molding compositions of the invention can comprise, as component C),from 0 to 230% by weight, in particular up to 100% by weight, of furtheradded substances and processing aids, where these differ from B) and/orfrom A), based on the weight of component A).

By way of example, conventional added substances C) are amounts of up to66% by weight, preferably up to 18% by weight, of elastomeric polymers(also often termed impact modifiers, elastomers, or rubbers).

These very generally involve copolymers, which are preferably composedof at least two of the following monomers: ethylene, propylene,butadiene, isobutene, isoprene, chloroprene, vinyl acetate, styrene,acrylonitrile, and acrylates and, respectively, methacrylates havingfrom 1 to 18 carbon atoms in the alcohol component.

Polymers of this type are described, for example, in Houben-Weyl,Methoden der organischen Chemie, Vol. 14/1 (Georg Thieme Verlag,Stuttgart, 1961), pages 392 to 406, and in the monograph by C. B.Bucknall, “Toughened Plastics” (Applied Science Publishers, London,1977).

Some preferred types of such elastomers are described below.

Preferred types of elastomers are those known as ethylene-propylene(EPM) and ethylene-propylene-diene (EPDM) rubbers.

EPM rubbers generally have practically no residual double bonds, whereasEPDM rubbers may have from 1 to 20 double bonds per 100 carbon atoms.

Examples which may be mentioned of diene monomers for EPDM rubbers areconjugated dienes, such as isoprene and butadiene, non-conjugated dieneshaving from 5 to 25 carbon atoms, such as 1,4-pentadiene, 1,4-hexadiene,1,5-hexadiene, 2,5-dimethyl-1,5-hexadiene and 1,4-octadiene, cyclicdienes, such as cyclopentadiene, cyclohexadienes, cyclooctadienes anddicyclopentadiene, and also alkenylnorbornenes, such as5-ethylidene-2-norbornene, 5-butylidene-2-norbornene,2-methallyl-5-norbornene and 2-isopropenyl-5-norbornene, andtricyclodienes, such as 3-methyltricyclo[5.2.1.0^(2,6)]-3,8-decadiene,or a mixture of these. Preference is given to 1,5-hexadiene,5-ethylidenenorbornene and dicyclopentadiene. The diene content of theEPDM rubbers is preferably from 0.5 to 50% by weight, in particular from1 to 8% by weight, based on the total weight of the rubber.

EPM and EPDM rubbers may preferably also have been grafted with reactivecarboxylic acids or with derivatives of these. Examples of these areacrylic acid, methacrylic acid and derivatives thereof, e.g. glycidyl(meth)acrylate, and also maleic anhydride.

Copolymers of ethylene with acrylic acid and/or methacrylic acid and/orwith the esters of these acids are another group of preferred rubbers.The rubbers may also comprise dicarboxylic acids, such as maleic acidand fumaric acid, or derivatives of these acids, e.g. esters andanhydrides, and/or monomers comprising epoxy groups. These monomerscomprising dicarboxylic acid derivatives or comprising epoxy groups arepreferably incorporated into the rubber by adding to the monomer mixturemonomers comprising dicarboxylic acid groups and/or epoxy groups andhaving the general formula I or II or III or IV

where R¹ to R⁹ are hydrogen or alkyl groups having from 1 to 6 carbonatoms, and m is a whole number from 0 to 20, g is a whole number from 0to 10 and p is a whole number from 0 to 5.

R¹ to R⁹ are preferably hydrogen, where m is 0 or 1 and g is 1. Thecorresponding compounds are maleic acid, fumaric acid, maleic anhydride,allyl glycidyl ether and vinyl glycidyl ether.

Preferred compounds of the formulae I, II and IV are maleic acid, maleicanhydride and (meth)acrylates comprising epoxy groups, such as glycidylacrylate and glycidyl methacrylate, and the esters with tertiaryalcohols, such as tert-butyl acrylate. Although the latter have no freecarboxy groups, their behavior approximates to that of the free acidsand they are therefore termed monomers with latent carboxy groups.

The copolymers are advantageously composed of from 50 to 98% by weightof ethylene, from 0.1 to 20% by weight of monomers comprising epoxygroups and/or methacrylic acid and/or monomers comprising anhydridegroups, the remaining amount being (meth)acrylates.

Particular preference is given to copolymers composed of

from 50 to 98% by weight, in particular from 55 to 95% by weight, ofethylene,from 0.1 to 40% by weight, in particular from 0.3 to 20% by weight, ofglycidyl acrylate and/or glycidyl methacrylate, (meth)acrylic acidand/or maleic anhydride, andfrom 1 to 45% by weight, in particular from 10 to 40% by weight, ofn-butyl acrylate and/or 2-ethylhexyl acrylate.

Other preferred (meth)acrylates are the methyl, ethyl, propyl, isobutyland tert-butyl esters.

Besides these, comonomers which may also be used are vinyl esters andvinyl ethers.

The ethylene copolymers described above may be produced by processesknown per se, preferably by random copolymerization at high pressure andelevated temperature. Appropriate processes are well known.

Other preferred elastomers are emulsion polymers whose production isdescribed, for example, by Blackley in the monograph “Emulsionpolymerization”. The emulsifiers and catalysts which can be used areknown per se.

In principle it is possible to use homogeneously structured elastomersor those with a shell structure. The shell-type structure is determinedby the sequence of addition of the individual monomers. The morphologyof the polymers is also affected by this sequence of addition.

Monomers which may be mentioned here, merely as examples, for theproduction of the rubber fraction of the elastomers are acrylates, suchas n-butyl acrylate and 2-ethylhexyl acrylate, correspondingmethacrylates, butadiene and isoprene, and also mixtures of these. Thesemonomers may be copolymerized with other monomers, such as styrene,acrylonitrile, vinyl ethers and with other acrylates or methacrylates,such as methyl methacrylate, methyl acrylate, ethyl acrylate or propylacrylate.

The soft or rubber phase (with a glass transition temperature of below0° C.) of the elastomers may be the core, the outer envelope or anintermediate shell (in the case of elastomers whose structure has morethan two shells). Elastomers having more than one shell may also havemore than one shell made from a rubber phase.

If one or more hard components (with glass transition temperatures above20° C.) are involved, besides the rubber phase, in the structure of theelastomer, these are generally produced by polymerizing, as principalmonomers, styrene, acrylonitrile, methacrylonitrile, α-methylstyrene,p-methylstyrene, or acrylates or methacrylates, such as methyl acrylate,ethyl acrylate or methyl methacrylate. Besides these, it is alsopossible to use relatively small proportions of other comonomers here.

It has proven advantageous in some cases to use emulsion polymers whichhave reactive groups at the surface. Examples of groups of this type areepoxy, carboxy, latent carboxy, amino and amide groups, and alsofunctional groups which may be introduced by concomitant use of monomersof the general formula

where the definitions of the substituents can be as follows:R¹⁰ hydrogen or a C₁-C₄-alkyl group,R¹¹ hydrogen, a C₁-C₈-alkyl group or an aryl group, in particularphenyl,R¹² hydrogen, a C₁-C₁₀-alkyl group, a C₆-C₁₂-aryl group, or —OR¹³R¹³ a C₁-C₈-alkyl group or a C₆-C₁₂-aryl group, if appropriate withsubstitution by O— or N-containing groups,X a chemical bond or a C₁-C₁₀-alkylene group, or a C₆-C₁₂-arylene group,or

Y O—Z or NH—Z, and

Z a C₁-C₁₀-alkylene group or a C₆-C₁₂-arylene group.

The graft monomers described in EP-A 208 187 are also suitable forintroducing reactive groups at the surface.

Other examples which may be mentioned are acrylamide, methacrylamide andsubstituted acrylates or methacrylates, such as (N-tert-butylamino)ethylmethacrylate, (N,N-dimethylamino)ethyl acrylate,(N,N-dimethylamino)methyl acrylate and (N,N-diethylamino)ethyl acrylate.

The particles of the rubber phase may also have been crosslinked.Examples of crosslinking monomers are 1,3-butadiene, divinylbenzene,diallyl phthalate and dihydrodicyclopentadienyl acrylate, and also thecompounds described in EP-A 50 265.

It is also possible to use the monomers known as graft-linking monomers,i.e. monomers having two or more polymerizable double bonds which reactat different rates during the polymerization. Preference is given to theuse of compounds of this type in which at least one reactive grouppolymerizes at about the same rate as the other monomers, while theother reactive group (or reactive groups), for example, polymerize(s)significantly more slowly. The different polymerization rates give riseto a certain proportion of unsaturated double bonds in the rubber. Ifanother phase is then grafted onto a rubber of this type, at least someof the double bonds present in the rubber react with the graft monomersto form chemical bonds, i.e. the phase grafted on has at least somedegree of chemical bonding to the graft base.

Examples of graft-linking monomers of this type are monomers comprisingallyl groups, in particular allyl esters of ethylenically unsaturatedcarboxylic acids, for example allyl acrylate, allyl methacrylate,diallyl maleate, diallyl fumarate and diallyl itaconate, and thecorresponding monoallyl compounds of these dicarboxylic acids. Besidesthese there is a wide variety of other suitable graft-linking monomers.For further details reference may be made here, for example, to U.S.Pat. No. 4,148,846.

The proportion of these crosslinking monomers in the impact-modifyingpolymer is generally up to 5% by weight, preferably not more than 3% byweight, based on the impact-modifying polymer.

Some preferred emulsion polymers are listed below. Mention may first bemade here of graft polymers with a core and with at least one outershell, and having the following structure:

Type Monomers for the core Monomers for the envelope I 1,3-butadiene,isoprene, n-butyl styrene, acrylonitrile, methyl acrylate, ethylhexylacrylate, methacrylate or a mixture of these II as I, but withconcomitant as I use of crosslinking agents III as I or II n-butylacrylate, ethyl acrylate, methyl acrylate, 1,3-butadiene, isoprene,ethylhexyl acrylate IV as I or II as I or III, but with concomitant useof monomers having reactive groups, as described herein V styrene,acrylonitrile, methyl first envelope made of methacrylate, or a mixturemonomers as described under of these I and II for the core, secondenvelope as described under I or IV for the envelope

These graft polymers, in particular ABS polymers and/or ASA polymers,are preferably used in amounts of up to 40% by weight forimpact-modification of PBT, if appropriate in a mixture with up to 40%by weight of polyethylene terephthalate. Appropriate blend products areobtainable with trademark Ultradur®S (previously Ultrablend®S from BASFAG).

Instead of graft polymers whose structure has more than one shell, it isalso possible to use homogeneous, i.e. single-shell, elastomers madefrom 1,3-butadiene, isoprene and n-butyl acrylate or from copolymers ofthese. These products, too, may be produced by concomitant use ofcrosslinking monomers or of monomers having reactive groups.

Examples of preferred emulsion polymers are n-butylacrylate-(meth)acrylic acid copolymers, n-butyl acrylate-glycidylacrylate or n-butyl acrylate-glycidyl methacrylate copolymers, graftpolymers with an inner core made from n-butyl acrylate or based onbutadiene and with an outer envelope made from the abovementionedcopolymers, and copolymers of ethylene with comonomers which supplyreactive groups.

The elastomers described can also be produced by other conventionalprocesses, e.g. via suspension polymerization.

Preference is likewise given to silicone rubbers, as described in DE-A37 25 576, EP-A 235 690, DE-A 38 00 603 and EP-A 319 290.

It is also possible, of course, to use a mixture of the types of rubberlisted above.

Fibrous or particulate fillers C) that may be mentioned are glassfibers, glass beads, amorphous silica, asbestos, calcium silicate,calcium metasilicate, magnesium carbonate, kaolin, chalk, powderedquartz, mica, barium sulfate, and feldspar. The amounts used of fibrousfillers C) are up to 150% by weight, in particular up to 50% by weight,and the amounts used of particulate fillers are up to 45% by weight, inparticular up to 10% by weight, based on the amount of component A).

Preferred fibrous fillers that may be mentioned are aramid fibers andpotassium titanate fibers, and particular preference is given here toglass fibers in the form of E glass. These can be used in the form ofrovings or of chopped glass in the forms commercially obtainable.

The amounts used of fillers that have high laser absorbency, for examplecarbon fibers, carbon black, graphite, graphene, or carbon nanotubes,are preferably below 1% by weight, particularly preferably below 0.05%by weight, based on the amount of component A).

The fibrous fillers can have been surface-pretreated with a silanecompound in order to improve compatibility with the thermoplastic.

Suitable silane compounds are those of the general formula

(X—(CH₂)_(n))_(k)—Si—(O—C_(m)H_(2m+1))_(4−k)

where the definitions of the substituents are as follows:

X NH₂—,

HO—,

n is an integer from 2 to 10, preferably from 3 to 4m is an integer from 1 to 5, preferably from 1 to 2k is an integer from 1 to 3, preferably 1.

Preferred silane compounds are aminopropyltrimethoxysilane,aminobutyltrimethoxysilane, aminopropyltriethoxysilane,aminobutyltriethoxysilane, and also the corresponding silanes whichcomprise a glycidyl group as substituent X.

The amounts generally used for surface coating of the silane compoundsare from 0.05 to 5% by weight, preferably from 0.1 to 1.5% by weight,and in particular 0.2 to 0.5% by weight (based on C).

Acicular Mineral Fillers are Also Suitable.

For the purposes of the invention, acicular mineral fillers are amineral filler with pronounced acicular character. An example that maybe mentioned is acicular wollastonite. The L/D (length to diameter)ratio of the mineral is preferably from 8:1 to 35:1, with preferencefrom 8:1 to 11:1. The mineral filler can, if appropriate, have beenpretreated with the abovementioned silane compounds; however, thepretreatment is not essential.

The thermoplastic molding compositions of the invention can comprise, ascomponent C), conventional processing aids, such as stabilizers,oxidation retarders, agents to counteract decomposition by heat anddecomposition by ultraviolet light, lubricants and mold-release agents,colorants, such as dyes and pigments, plasticizers, etc.

Examples of oxidation retarders and heat stabilizers are stericallyhindered phenols and/or phosphites, hydroquinones, aromatic secondaryamines, such as diphenylamines, and various substituted representativesof these groups, and mixtures of these, at concentrations of up to 1% byweight, based on the weight of the thermoplastic molding compositions.

UV stabilizers that may be mentioned, generally used in amounts of up to2% by weight, based on the molding composition, are various substitutedresorcinols, salicylates, benzotriazoles, and benzophenones.

Colorants that can be added comprise inorganic and organic pigments, andalso dyes, such as nigrosin, and anthraquinones. Particularly suitablecolorants are mentioned by way of example in EP 1722984 B1, EP 1353986B1, or DE 10054859 A1.

Preference is further given to esters or amides of saturated orunsaturated aliphatic carboxylic acids having from 10 to 40, preferablyfrom 16 to 22, carbon atoms with saturated aliphatic alcohols or amineswhich comprise from 2 to 40, preferably from 2 to 6, carbon atoms.

The carboxylic acids can be monobasic or dibasic. Examples that may bementioned are pelargonic acid, palmitic acid, lauric acid, margaricacid, dodecanedioic acid, behenic acid, and with particular preferencestearic acid, and capric acid, and also montanic acid (a mixture offatty acids having from 30 to 40 carbon atoms).

The aliphatic alcohols can be mono- to tetrahydric. Examples of alcoholsare n-butanol, n-octanol, stearyl alcohol, ethylene glycol, propyleneglycol, neopentyl glycol, and pentaerythritol, preference being givenhere to glycerol and pentaerythritol.

The aliphatic amines can be mono- to trifunctional. Examples of theseare stearylamine, ethylenediamine, propylenediamine,hexamethylenediamine, and di(6-aminohexyl)amine, particular preferencebeing given here to ethylenediamine and hexamethylenediamine. Preferredesters or amides are correspondingly glycerol distearate, glyceroltristearate, ethylenediamine distearate, glycerol monopalmitate,glycerol trilaurate, glycerol monobehenate, and pentaerythritoltetrastearate.

It is also possible to use a mixture of various esters or amides, oresters combined with amides, in any desired mixing ratio.

The amounts usually used of further lubricants and mold-release agentsare usually up to 1% by weight, based on the amount of component A). Itis preferable to use long-chain fatty acids (e.g. stearic acid orbehenic acid), salts of these (e.g. Ca stearate or Zn stearate), ormontan waxes (mixtures made of straight-chain, saturated carboxylicacids having chain lengths of from 28 to 32 carbon atoms), or else Camontanate or Na montanate, or else low-molecular-weight polyethylenewaxes or low-molecular-weight polypropylene waxes.

Examples that may be mentioned of plasticizers are dioctyl phthalate,dibenzyl phthalate, butyl benzyl phthalate, hydrocarbon oils, andN-(n-butyl)benzenesulfonamide.

The molding compositions of the invention can also comprise from 0 to 2%by weight of fluorine-containing ethylene polymers, based on the amountof component A). These are polymers of ethylene having fluorine contentof from 55 to 76% by weight, preferably from 70 to 76% by weight.

Examples here are polytetrafluoroethylene (PTFE),tetrafluoroethylene-hexafluoropropylene copolymers, ortetrafluoroethylene copolymers having relatively small proportions(generally up to 50% by weight) of copolymerizable ethylenicallyunsaturated monomers. These are described by way of example bySchildknecht in “Vinyl and Related Polymers”, Wiley-Verlag, 1952, pages484 to 494, and by Wall in “Fluoropolymers” (Wiley Interscience, 1972).

These fluorine-containing ethylene polymers have homogeneousdistribution in the molding compositions and preferably have a(number-average) d₅₀ particle size in the range from 0.05 to 10 μm, inparticular from 0.1 to 5 μm. These small particle sizes can beparticularly preferably achieved via use of aqueous dispersions offluorine-containing ethylene polymers and incorporation of these into apolyester melt.

The thermoplastic molding compositions of the invention can be producedby processes known per se, by mixing the starting components inconventional mixing apparatuses, such as screw extruders, Brabendermixers, or Banbury mixers, and then extruding the same. The extrudatecan be cooled and comminuted. It is also possible to premix individualcomponents (e.g. applying component B) to the pellets, for example in adrum), then adding the remaining starting materials individually and/orafter they have been likewise mixed. The mixing temperatures aregenerally from 230 to 290° C. Component B) can also preferably be addedto the extruder inlet by the hot-feed or direct method.

In another preferred method of operation, components B) and also, ifappropriate, C) can be mixed with a polyester prepolymer, and compoundedand pelletized. The resultant pellets are then solid-phase condensedunder inert gas continuously or batchwise at a temperature below themelting point of component A) until the desired viscosity has beenreached.

The molding compositions that can be used in the invention are suitablefor producing laser-transparent moldings. The laser transparency ofthese is preferably at least 33%, in particular at least 40%,specifically at least 50% (at 1064 nm, measured on moldings of thickness2 mm by the test method described in the examples).

Laser-transparent moldings of this type are used in the invention toproduce moldings by means of laser transmission welding processes.

The use preferably serves for producing moldings via laser transmissionwelding. Laser transmission welding is preferably used here to bond thelaser-transparent moldings to laser-absorbent moldings.

Moldings made of any laser-absorbent materials can generally be used aslaser-absorbent molding. By way of example, composite materials orthermosets can be used here, or preferably moldings made from specificthermoplastic molding compositions. Suitable thermoplastic moldingcompositions are molding compositions which have adequate laserabsorption within the wavelength range used. Suitable thermoplasticmolding compositions can by way of example preferably be thermoplasticswhich are laser-absorbent by virtue of addition of inorganic pigments,such as carbon black, and/or by virtue of addition of organic pigmentsor of other additives. Examples of suitable organic pigments forachieving laser absorption are preferably IR-absorbent organiccompounds, for example those described in DE 199 16 104 A1.

The invention further provides moldings and/or molding combinations, towhich moldings of the invention have been bonded by laser transmissionwelding.

Moldings of the invention have excellent suitability for durable andstable attachment to laser-absorbent moldings by the laser transmissionwelding process. They are therefore particularly suitable for materialsfor covers, housings, add-on components, and sensors, for example forapplications in the motor-vehicle, electronics, telecommunications,information-technology, computer, household, sports, medical, orentertainment sector.

EXAMPLES Component A/1:

Polybutylene terephthalate with intrinsic viscosity 130 ml/g and havingterminal carboxy group content of 34 meq/kg (Ultradur® B 4500 from BASFSE) (IV measured in 0.5 strength by % solution ofphenol/o-dichlorobenzene, 1:1 mixture, at 25° C.).

Component B)

E1 Sodium benzoate E2 Sodium 4-tert-butylbenzoate E3 Disodium salicylateE4 Disodium 4-hydroxybenzenesulfonate E5 Lithium 5-sulfoisophthalate E6Sodium 2-nitrobenzoate E7 Sodium 2-chlorobenzoate E8 Sodium2,4-dichlorobenzoate E9 Sodium phenylacetate E10 Sodium isonicotinateE11 Sodium 2-thiophenecarboxylic acid E12 Sodium pyrrole-2-carboxylateE13 Sodium phenolate

Component C

Glass fibers: diameter 10 μm, sized for polyester, DS3185 from 3B.

The molding compositions were produced in a ZSK25 at from 250 to 260°C., flat temperature profile, and pelletization.

Laser Transparency Measurement

Laser transmittance was determined at wavelength 1064 nm means ofthermoelectric power measurement. The measurement geometry was set up asfollows: a beam divider (SQ2 non-polarizing beam divider from LaseroptikGmbH) was used to divide a reference beam of power 1 watt at an angle of90° from a laser beam (diode-pumped Nd—YAG laser with wavelength 1064nm, FOBA DP50) with total power of 2 watts. The reference beam impactedthe reference sensor. That portion of the original beam that passedthrough the beam divider provides the measurement beam likewise withpower of 1 watt. This beam was focused to a focal diameter of 0.18 μmvia a mode diaphragm (5.0) behind the beam divider. The lasertransparency (LT) measurement sensor was positioned 80 mm below thefocus. The test sheet was positioned 2 mm above the LT measurementsensor. Injection-molded test sheets are used, with dimensions 60*60*2mm³ and with edge gating. The measurement was made in the middle of thesheet (point of intersection of the two diagonals). Theinjection-molding parameters were set to the following values:

Melt temp. Mold temp. Injection rate Hold pressure [° C.] [° C.] [cm³/s][bar] Unreinforced 260 60 48 600 materials Reinforced 260 80 48 600materials

The total measurement time was 30 s, and the result of the measurementis determined within the final 5 s. The signals from the referencesensor and measurement sensor were recorded simultaneously. Themeasurement process begins with insertion of the specimen.Transmittance, and therefore laser transparency, was obtained from thefollowing formula:

LT=(Signal(measurement sensor)/Signal(reference sensor))×100%.

This measurement method excluded variations in the laser system andsubjective read-out errors.

The average LT value for a sheet was calculated from at least fivemeasurements. For each material, the average value was calculated on 10sheets. The average values from the measurements on the individualsheets were used to calculate the average value, and also the standarddeviation, for the material.

Transmittance Spectra (Ulbricht Measurement)

Transmission spectra were measured using Ulbricht sphere measurementgeometry in the wavelength range from 300 to 2500 nm. Ulbricht spheresare hollow spheres, the inner surfaces of which provide high andunoriented (diffuse) reflection over a broad spectral range. Whenradiation impacts the inner surface of the sphere, it undergoes multiplereflection until it has completely uniform distribution within thesphere. This integration of the radiation averages all of the effectsdue to angle of incidence, shadowing, modes, polarization, and otherproperties. As a function of the configuration of the Ulbricht sphere,the detector attached within the sphere records only diffusetransmittance, or the sum of directed and diffuse transmittance (=totaltransmittance).

A Varian Cary 5000 spectrometer with attached DRA 2500 Ulbricht systemwas used in transmission mode (specimen between radiation source andUlbricht sphere). To measure total transmittance, a white reflector(Labsphere Spectralon Standard) was used to close the reflection portopposite to the specimen. To measure the diffuse transmittance fraction,a black light trap (DRA 2500 standard light trap) was used to close thereflection port. Transmittance was stated in relation to the intensityof incident radiation. Oriented transmittance was calculated as thedifference between total transmittance and diffuse transmittance.Oriented transmittance is stated in relation to total transmittance:

${{Oriented}\mspace{14mu} {transmittance}} = \frac{\left( {{{total}\mspace{14mu} {transmittance}} - {{diffuse}\mspace{14mu} {transmittance}}} \right) \times 100\%}{{total}\mspace{14mu} {transmittance}}$

TABLE 1 Amount of B Amount of B LT @ 1064 nm Component [% by wt.][mmol/kg of PBT] [% T] Reference 0 0 30 E1 0.5 34.7 55 E2 0.5 25.0 42 E30.5 27.05 61 E4 0.5 22.9 36 E5 0.5 19.8 35 E6 0.5 26.4 41 E7 0.5 31.9 43E8 0.5 23.5 39 E9 0.5 31.6 49 E10 0.5 34.5 51 E11 0.5 33.3 45 E12 0.537.6 60 E13 0.5 43.1 51

TABLE 2 Mechanical properties of selected unreinforced formulations:99.5% of 100% by weight of A/1 A/1 + reference 0.5% of B1 Modulus ofelasticity [MPa] 2511 2882 Tensile strength [MPa] 56.4 57.2 Tensilestrain at break [%] 170 2.4 Impact resistance [kJ/m{circumflex over( )}2] no fracture 31.3 without notchTensile test to ISO 527. Impact resistance test to ISO 179.

TABLE 3 Amount of B Amount of B LT @ 1064 nm Component [% by wt.][mmol/kg of PBT] [% T] Reference 0 30 E1 0.01 0.7 30 E1 0.1 6.9 25 E10.2 13.9 30 E1 0.3 20.8 41 E1 0.4 27.8 47 E1 0.5 34.7 50 E1 0.75 52.0 56E1 1 69.4 58 E1 1.5 104.1 55 E1 2 138.8 44

TABLE 4 Ulbricht transmittance measurements on selected formulations:Oriented Total transmittance transmittance fraction [%] [%] Wavelength99.5% of A/1 99.5% of A/1 range 0.5% by wt. of 0.5% by wt. of [nm]Reference B1 Reference B1 400-600 10-20  2-24 0-2 0-2 600-800 20-2724-37 0-2 0-4  800-1000 27-30 37-46 0-2  4-27 1000-1100 30-32 46-50 0-227-43 1100-1200 abs abs 0-2 43-64 1200-1600 18-33 45-67 0-2 62-901600-1630 20-30 60-66 0-5 90-92 1630-1800 abs abs 0-5 92-95 1800-2100 7-14 51-59 0-2 95-97 2100-2200 abs abs 0-5 97-98 abs:absorption-dependent transparency change (band)

TABLE 5 Concentration series, reinforced (in B4500 + 30% by weight ofglass fibers) Amount of B Amount of B LT @ 1064 nm Component [% by wt.][mmol/kg of PBT] [% T] Reference 0 0 27 E1 0.01 0.9 27 E1 0.1 9.2 18 E10.3 27.7 36 E1 0.5 46.1 47 E1 0.75 69.2 52

TABLE 6 Mechanical properties of selected reinforce formulations:Reference +0.5% of B1 Modulus of elasticity [MPa] 9564 10 485 Tensilestrength [MPa] 136   140 Tensile strain at break [%] 3.4      2.2 Impactresistance with notch [kJ/m²] 9.8      8.1 Reference: 70% by weight ofA/1 + 30% by weight of C

1.-12. (canceled)
 13. A laser-transparent molding of any type,comprising a thermoplastic molding compositions comprising, A) apolyester, B) from 20 to 200 mmol/kg of polyester A) of at least onecompound of the general formula (I)

where respectively independently at any position -A¹- is —NR—, —O—, —S—,—CH=A⁴- where R is H or C₁₋₆-alkyl, A⁴ is N or CH A² is COOX or OX,where X is Li, Na, K, Rb, Cs, Mg/2, Ca/2, Sr/2, Ba/2, Al/3 A³ isC₁₋₆-alkyl, C₆₋₁₂-aryl, C₇₋₁₃-alkaryl, C₇₋₁₃-aralkyl, O—C₁₋₆-alkyl,O—C₆₋₁₂-aryl, O—C₇₋₁₃-alkaryl, O—C₇₋₁₃-aralkyl, COOX′, OX′, SX′, SO₃X′,where X′ is H or X, S—C₁₋₆-alkyl, S—C₆₋₁₂-aryl, NR₂, halogen, or NO₂, nis an integer from 1 to 4, and m is an integer from 0 to 4−n, where m=1,if A³=NO_(2‘,) with the proviso that the number of mmol is based on thegroup(s) COOX and OX and SX′ where X′═X, to the extent that these arepresent in the compound of the general formula (I); and C) from 0 to230% by weight of further added substances, based on the weight ofcomponent A).
 14. The molding according to claim 13, where the moldingcompositions comprise from 25 to 140 mmol/kg of polyester A of componentB).
 15. The molding according to claim 13, where the laser transparencyof the molding is at least 33% (measured at 1064 nm on a molding ofthickness 2 mm).
 16. The molding according to claim 13, wherein n hasthe value 1 or 2, and m has the value 0 or 1 or
 2. 17. The moldingaccording to claim 16, wherein n has the value 1 and m has the value 0or
 1. 18. The molding according to claim 13, wherein X is Li, Na, K, Rbor Cs.
 19. The molding according to claim 18, wherein X is Li, Na or K.20. The molding according to claim 13, wherein A³ is C₁₋₆-alkyl, OX,SO₃X, halogen or NO₂.
 21. The molding according to claim 13 obtained vialaser transmission welding.
 22. The moldings according to claim 13,wherein laser transmission welding is used to bond the laser-transparentmoldings to laser-absorbent moldings.
 23. A process for producing weldedmoldings, which comprises using laser transmission welding to bondlaser-transparent moldings as defined in claim 13 to laser-absorbentmoldings.
 24. A welded molding obtainable according to the process ofclaim 23, which is suitable for applications in the electrical,electronic, telecommunications, information-technology, computer,household, sports, medical, motor-vehicle or entertainment sector.